Scrapie has compromised the health of small ruminants for centuries. The disease was first described in 1732 and is now recognized as a transmissible spongiform encephalopathy ( TSE ). A recent article in Animal Frontiers , by Dr. V. Beringue and Dr. O. Andreoletti, describes how the specter of this "old" disease has remerged in a "new" form. The old, well-known TSE...